CN111884019B - Three-dimensional multi-beam laser parameter regulation and control method and system - Google Patents

Abstract

The invention relates to a three-dimensional multi-beam laser parameter control method and system, including initializing a laser system, obtaining a hologram of an output light field and generating multi-beam laser beams, and the multi-beam laser beams are incident on the spot energy and position transmission through an optical path. On the sensor component; the spot energy and position sensor components sequentially collect the energy and position information of all laser beams whose focal points are not in the same plane, and perform feedback modulation to match the preset target energy and position information, and the laser system controls the optical path to switch to Make multiple laser beams incident on the target area through the optical path. The invention dynamically adjusts the energy and position information of each laser beam, monitors the parameter information and quality of the output beam in real time, has flexible control, ensures that each laser beam incident on the target area reaches the corresponding set target, and effectively reduces the optical system. error, each laser beam can be modulated arbitrarily and accurately, and the utilization rate of the laser can be doubled.

Description

A three-dimensional multi-beam laser parameter control method and system

technical field

The invention relates to the technical field of laser processing, in particular to a three-dimensional multi-beam laser parameter control method and system.

Background technique

Multi-beam control technology usually refers to the technology of controlling various parameters of multiple laser beams at the same time. Common controllable parameters include parameters such as the number of beams, direction, light intensity distribution (mode), light intensity and light power. When the beam converges on the spherical wavefront, the beam can be converged into a light spot in three-dimensional space after passing through the positive lens, and the axial distance of the light spot can be controlled by changing the position of the positive lens or the focal length of the lens. If combined with the beam pointing control technology , this light spot has three-dimensional space controllability. Three-dimensional multi-beam is widely used in medicine, optics, physics, microelectronics and laser communication, laser processing, lidar and other fields.

The methods of generating three-dimensional multi-beams include: microlens array method, multi-laser method, diffractive optical element method, programmable diffractive device method, etc. The first three types of methods can only be applied to application scenarios with fixed spacing or periodic structures, which have poor application flexibility, cannot achieve parameter control of any beam in three dimensions, and are difficult to meet the requirements of mass production of arbitrary structures.

The parameter control of three-dimensional multi-beam is realized based on programmable diffractive devices. The hologram is mainly calculated by different algorithms, which can change the quantity of light, spatial position, energy distribution, energy intensity, etc. The key to modulating light in this method is the hologram, and the key to generating the phase map is the algorithm. The current mainstream algorithms are divided into two categories: 1) Non-iterative algorithms, such as GL algorithm, RM algorithm, S algorithm, SR algorithm, etc. , this algorithm is characterized by fast calculation speed, but low diffraction efficiency, large calculation error, and it is difficult to achieve accurate control; 2) Iterative algorithms, such as GS algorithm, GAA algorithm, DS algorithm, GSW algorithm, ORA algorithm, etc., this algorithm The characteristic is that the diffraction efficiency is high, the calculation error is small, but the calculation speed is slow.

In the actual use process, the iterative algorithm only iterates within the algorithm, and the parameter results of the actual multi-beam cannot be detected and judged. When there are light source errors, device installation errors, manufacturing errors and other influencing factors in the optical path, the calculation will eventually appear. The error of the hologram is large, which cannot meet the needs of practical applications.

For example, the Chinese Patent Publication No. CN109079318B disclosed on April 24, 2020 a femtosecond laser preparation system and method based on a silicon photonic crystal waveguide based on a spatial light modulator, the patent modulates the light beam through the spatial light modulator, To achieve multi-beam parallel processing, the number and distribution of beams in parallel processing are checked by observing the images captured by the CCD camera. As we all know, the CCD camera, as an integral detection device, indirectly calculates the distance corresponding to each pixel from the grayscale of the obtained image through modulation/solution, and then obtains the three-dimensional image of the target. It is impossible to observe each pixel from the CCD image. Laser beam energy information. The patent does not disclose how to observe and judge the occurrence of errors in each laser beam in the multi-beam, nor how to adjust the wrong laser beams without affecting other correct laser beams when errors occur. However, only through the "modification in the computer" disclosed in the patent specification, it cannot be obtained that the faulty laser beam is iteratively modulated, and it cannot be determined that the closed-loop feedback control is performed. On the basis of this patent, those skilled in the art need further research. The difficulty of the research process lies in how to judge whether the actual state of the position and energy of any laser beam in the multi-beam matches the target state, and how to determine whether the actual state of the position and energy of the beam in the multi-beam matches. When the state does not match the target state, how to adjust and control according to the real-time laser beam state, and then obtain a laser beam that matches the preset state of the laser beam, so as to ensure that each laser beam incident on the target area reaches the corresponding position and energy The set target can effectively reduce the error of the optical system.

The Chinese patent with publication number CN107065124A disclosed on August 18, 2017 a method for realizing beam focus feedback control based on a liquid crystal spatial light modulator. The area array detector realizes real-time feedback control of the focus point position. Since the patent application does not involve multi-beam parallel processing, its control method does not involve individually regulating the position and energy of each laser beam in the multi-beam. In addition, the CCD camera is one of the area array detectors, and the patent application, like the patent with publication number CN109079318B, has the problem that the real-time energy information of each laser beam in the multi-beam cannot be obtained.

It can be seen that the prior art does not disclose the detection and judgment of the actual position and energy information of the multi-beam, and iterative modulation of the output laser beam is performed according to the actual detection result, so that the real-time state of each laser beam in the multi-beam is consistent with the target. Status matches the content. Moreover, at present, most of the multi-beam parallel processing on the market cannot simultaneously adjust the position and energy of any beam in the multi-beam, and cannot effectively utilize all the energy output by the laser. The laser processing efficiency and flexibility are low, which limits the multi-beam parallel processing. application.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a three-dimensional multi-beam laser parameter control method and system aiming at the deficiencies of the above-mentioned prior art.

The technical scheme that the present invention solves the above-mentioned technical problems is as follows:

According to an aspect of the present invention, a three-dimensional multi-beam laser parameter control method is provided, the method comprising the following steps:

Step 11: initialize the system, obtain the hologram of the output light field, and generate multiple laser beams according to the hologram, and the multiple beams of the laser beams are incident on the detection area;

Step 12: Adjust the distance between the outgoing laser beam and the detection components in the detection area, sequentially detect the energy and position information of all laser beams incident on different planes, and determine the real-time energy and position information of each laser beam and the corresponding beam Whether the preset energy of the laser beam and the position information match, if so, the real-time state of the laser beam matches the preset state, and go to step 14; otherwise, go to step 13;

Step 13: Modulate the energy and position information of the mismatched laser beam, generate a new hologram according to the modulated energy and position information, and generate a new laser beam according to the new hologram, and the new laser beam is incident to the detection area, and return to step 12 above;

Step 14: generating multiple laser beams according to the holograms corresponding to the energy and position information of all laser beams whose real-time state matches the preset state, and the multiple laser beams are incident on the target area;

In the step 12, the step of judging whether the real-time energy and position information of each laser beam matches the corresponding preset energy and position information further includes:

The actual energy value I _i of any laser beam and the actual position coordinate P _i satisfy the following preset matching conditions, then the real-time energy and position information of the laser beam matches the corresponding preset energy and position information, otherwise it does not match;

The preset matching conditions are:

𝛥 I _i = I _i - I _i—targ

𝛥 P _i = P _i - P _i—targ

𝛥 I _i <I𝜀

𝛥 P _i < P𝜀

Among them, I _i is the actual energy value of the i -th laser beam, I _i-targ is the target energy value of the i -th laser beam, P _i is the actual position coordinate of the i- th laser beam, and P _i-targ is the i -th laser beam The target position coordinates of the laser beam, 𝛥 I _i is the energy deviation value between the actual energy value of the ith laser beam and the target energy value, 𝛥 P _i is the actual position coordinates of the ith laser beam and the target position coordinates. Position coordinate deviation value, I𝜀 is the preset energy deviation threshold, P𝜀 is the preset position coordinate deviation threshold;

In the step 13, the step of modulating the energy and position information of the mismatched laser beams further includes:

Step 131: Correct according to the energy deviation value and the position coordinate deviation value, and the specific calculation formula is:

G _Ii =M _i *𝛥 I _i + I _i—targ

G _Pi =N _i *𝛥 P _i + P _i—targ

Step 132: Determine the updated image plane transformation phase and image plane light field amplitude according to the corrected energy value and position coordinate value;

Step 133: Perform inverse Fourier transform according to the updated image plane light field amplitude and the image plane transformation phase to obtain the modulated image plane light field amplitude and the modulated phase;

Wherein, M _i is the energy weighting coefficient of the i - th laser beam, N _i is the position coordinate weighting coefficient of the i-th laser beam, I _i-targ is the target energy value of the i- th laser beam, P _i-targ is the target position coordinate of the i -th laser beam, G _Ii is the corrected energy value of the i -th laser beam, G _Pi is the corrected position coordinate value of the i -th laser beam, and the value range of i is [1, k ], k is the total number of laser beams.

In the above technical solution, the energy and position information of each laser beam are accurately collected in turn by adjusting the distance between the focus of the outgoing laser beam and the detection component of the spot energy and position in the detection area, and fed back to the control terminal for closed-loop feedback. Control, dynamically adjust the energy and position information of each laser beam, monitor the parameter information and quality of the output beam in real time, flexible control, can eliminate the influence caused by optical device manufacturing and installation errors, so as to ensure that each laser beam incident on the target area The beams all reach the corresponding set targets, effectively reducing the optical system error, and the energy and position information of each laser beam can be arbitrarily controlled in the three-dimensional space to meet the needs of each laser beam in the target area. modulation, and doubled the laser utilization rate to meet the requirements of practical application scenarios.

In the above technical solution, it can be determined whether each laser beam meets the corresponding preset requirements through the preset matching condition formula, and iterative processing is performed when the preset requirements are not met, so as to finally realize the output of each laser beam to the target area. The beams conform to the pre-set targets, realizing the targeted control of multiple laser beams irradiated to the target area in three-dimensional space, so as to meet the requirements of arbitrary and precise regulation of multiple laser beams.

In the above technical solution, iterative modulation is performed when the energy and position information of the laser beam do not match the corresponding preset energy and position information, and the cycle is repeated until the energy and position information of each laser beam and the corresponding preset energy. Matching with the position information, so as to ensure that each laser beam incident on the surface of the workpiece reaches the corresponding set energy and position, so as to meet the arbitrary and precise control requirements of multiple laser beams.

On the basis of above-mentioned technical scheme, the present invention can also do following improvement:

Further: in the step 11, initializing the laser system specifically includes:

Step 111 : superimpose the random initial phase on the incident light field, and perform Fourier transform to obtain the corresponding light field distribution of the surface where the frequency domain is located, the amplitude of the surface light field where the frequency domain is located, and the phase of the surface where the frequency domain is located;

Step 112: Substitute the preset target light field amplitude for the amplitude of the surface light field where the frequency domain is located, and perform inverse Fourier transform according to the phase of the surface where the frequency domain is located, to obtain the updated light field distribution and spatial domain where the air domain is located. The amplitude of the light field on the surface and the phase of the surface where the space is located;

Step 113: generate a hologram according to the updated light field distribution of the surface where the airspace is located, the light field amplitude of the surface where the airspace is located, and the phase of the surface where the airspace is located;

Step 114: Load the hologram onto the laser system, and the laser system generates multiple laser beams according to the hologram.

The beneficial effects of the above-mentioned further scheme are: performing Fourier transform on a random initial phase to generate the distribution of the surface light field where the frequency domain is located, the amplitude of the surface light field where the frequency domain is located, and the surface phase where the frequency domain is located as a reference, and use the target light field amplitude instead of the frequency domain. The amplitude of the light field of the surface where the plane is located is inversely transformed to obtain a phase-generated hologram of the plane where the air domain is located, so as to determine the corresponding hologram, which is convenient for the beam parameter control component to generate multiple laser beams according to the hologram.

Further: in the step 12, the sequentially collecting the energy and position information of all laser beams whose focal points are not in the same plane specifically includes the following steps:

Step 121: the spot energy and position sensing assembly receives multiple laser beams, and generates a corresponding profile according to the laser beam whose focus is located on the plane where the spot energy and position sensing assembly is located;

Step 122: Collect the actual energy value I _i and the actual position coordinate P _i corresponding to all the light spots within the contour range;

Step 123: Adjust the relative positions of the spot energy and position sensing components and the focal points of the multiple laser beams, and repeat the above steps 121 and 122 until the actual energy values I _i and actual position coordinates P _i corresponding to all laser beams Collection is complete.

The beneficial effect of the above-mentioned further scheme is: by adjusting the relative position of the spot energy and position sensing component and the focal point of the corresponding laser beam, to realize the collection of energy and position information of the laser beam with the focal point on different planes, so that through the subsequent closed loop Feedback control, so that the energy and position information of each laser beam finally output achieves the purpose of setting the target, and realizes the targeted control of each laser beam in the three-dimensional space.

Further: in the step 123, the specific implementation of adjusting the relative positions of the spot energy and position sensing components and the focal points of the multiple laser beams is as follows:

Adjusting the distance between the focal point of the laser beam and the spot energy and position sensing assembly so that the spot energy and position sensing assembly collects laser light when the focal point of the laser beam is located on the plane of the spot energy and position sensing assembly beam energy and position information.

The beneficial effect of the above-mentioned further scheme is: by adjusting the distance between the focus of the laser beam emitted by the laser system and the spot energy and position sensing components, it can be ensured that the focus of each laser beam can be located in the adjustment process. The light spot energy and position sensing components are located on the plane, so that they can be accurately collected.

Further: in the step 123, the specific implementation of adjusting the relative positions of the spot energy and position sensing components and the focal points of the multiple laser beams is as follows:

A Fresnel lens phase hologram with adjustable parameters and a focal length shift function is superimposed on the hologram, and the focus of the stress beam is adjusted to the spot energy and position by adjusting the parameters of the Fresnel lens The sensing component is located on a plane, so that the light spot energy and position sensing component collects energy and position information of the corresponding laser beam.

The beneficial effects of the above-mentioned further scheme are: using a Fresnel lens phase hologram with adjustable focal length shift function superimposed on the hologram, and by adjusting the parameters of the Fresnel lens, the focus of the stress beam can be adjusted Adjusting to the plane where the light spot energy and position sensing components are located, it is possible to detect light spots of different focal planes without moving the light spot energy and position sensing components, and realize fast three-dimensional position detection and feedback without mechanical motion.

According to another aspect of the present invention, a three-dimensional multi-beam laser parameter control system is provided for implementing the method, the system includes a laser light source, an optical path deflection component, a beam parameter control component, a spot energy and a position sensor an assembly and a control terminal, the beam parameter adjustment assembly, the spot energy and position sensing assemblies are respectively connected with the control terminal;

The control terminal is used to initialize and generate a hologram of the output light field, and load the hologram onto the beam parameter control component;

The optical path deflection component is used for incident multiple laser beams on the spot energy and position sensing component located in the detection area, or incident on the working plane located in the target area;

the beam parameter control component is configured to receive the laser beam output by the laser light source, and generate multiple laser beams according to the hologram;

The light spot energy and position sensing component is used for receiving the laser beam, and sequentially collecting the energy and position information of all laser beams whose focal points are not in the same plane;

The control terminal is also used for judging whether the energy and position information of each laser beam matches the corresponding preset energy and position information, and when matching, controls the beam parameter adjustment component according to the description of all laser beams. The holograms corresponding to the energy and position information generate multiple laser beams; and when they do not match, perform iterative modulation processing according to the energy and position information of each laser beam, until the energy and position information of each laser beam are the same as The corresponding preset energy and position information are matched.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention sequentially and accurately collects the energy and position information of each laser beam by adjusting the distance between the focus of the outgoing laser beam and the spot energy and position sensing components, and feeds it back to the control terminal for closed-loop feedback control. Adjust the energy and position information of each laser beam, monitor the energy and position information and quality of the output beam in real time, and have flexible control, which can eliminate the influence caused by the manufacturing and installation errors of optical devices, so as to ensure that each laser beam incident on the target area is All achieve the corresponding set goals, effectively reduce the error of the optical system, and can arbitrarily control the energy and position information of each laser beam in the three-dimensional space, so that each laser beam in the target area can be modulated arbitrarily and accurately , and doubled the laser utilization rate to meet the requirements of practical application scenarios.

(2) The present invention judges the matching between the real-time state and the preset state of each laser beam, and performs iterative processing when the set requirements are not met, so that each laser beam output to the target area conforms to the preset state. Objective: Through the closed-loop feedback control of the real-time energy and position information of the laser beam, the energy and position information of each laser beam can be dynamically adjusted, so as to realize the independent and precise control of multiple parameters of any beam in the multi-laser beam, and effectively utilize The full output energy of the laser beam improves the laser processing efficiency.

Description of drawings

FIG. 1 is a schematic flowchart of a method for adjusting parameters of a three-dimensional multi-beam laser according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of collecting parameter information of different corresponding laser beams according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of collecting parameter information of the same corresponding laser beam according to an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a three-dimensional multi-beam laser parameter control system according to another embodiment of the present invention.

In the accompanying drawings, the list of components represented by each number is as follows:

1. Laser light source, 2. Polarization direction and energy adjustment component, 3. First reflector, 4. Beam parameter adjustment component, 5. First lens, 6. Second reflector, 7, Third reflector, 8, second lens, 9, flip mirror, 10, first focusing assembly, 11, linear stage, 12, spot energy and position sensing assembly, 13, fourth mirror, 14, second focusing assembly, 15, three-dimensional motion Workbench, 16. Control terminal.

Detailed ways

The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples are only used to explain the present invention, but not to limit the scope of the present invention.

Example 1

In this embodiment, the laser parameter control system includes a laser light source, an optical path deflection component, a beam parameter control component, a spot energy and position sensing component 12, and a control terminal 16. The beam parameter control component, the spot energy and position sensing components The components 12 are respectively connected with the control terminal 16; the control terminal 16 is used to initialize and generate a hologram of the output light field, and load the hologram onto the beam parameter control component; the optical path deflection component is used for In order to make multiple laser beams incident on the spot energy and position sensing component 12 located in the detection area, or incident on the working plane located in the target area; the beam parameter control component is used to receive the laser output from the laser light source. and generate multiple laser beams according to the hologram; the spot energy and position sensing assembly 12 is used to receive the laser beam, and collect multiple beams whose focal points are all located on the plane where the spot energy and position sensing assembly 12 is located The energy and position information of the laser beam; the control terminal 16 is also used to judge whether the energy and position information of each laser beam matches the corresponding preset energy and position information, and when matching, control the beam The parameter control component generates multiple laser beams according to the holograms corresponding to the energy and position information; and in the case of mismatch, iterative modulation processing is performed according to the energy and position information of each laser beam, until the The energy and position information are matched with corresponding preset energy and position information.

The optical path deflecting assembly is composed of a plurality of optical devices capable of realizing its functions. The light beam parameter control component adopts a programmable diffractive optical device. The light spot energy and position sensing assembly 12 adopts existing sensing devices that can realize its functions. The control terminal 16 adopts a computer, an industrial computer and other equipment capable of realizing its functions.

As shown in Figure 1, a three-dimensional multi-beam laser parameter control method includes the following steps:

Step 11: initialize the laser system for outputting the multi-beam laser, obtain the hologram of the output light field and generate multi-beam laser beams, and the multi-beam laser beams are incident on the spot energy and position sensing assembly 12 through the optical path; The incident light route of the laser beam is realized by the optical path deflection component.

Step 12: The spot energy and position sensing component 12 sequentially collects the energy and position information of all laser beams whose focal points are not in the same plane, and transmits them to the control terminal 16. The control terminal 16 judges the energy and position information of each laser beam and Whether the corresponding preset target energy and position information match, if so, the real-time state of the laser beam matches the preset state, and then go to step 14, otherwise go to step 13;

Step 13: The control terminal 16 modulates the energy and position information of the unmatched laser beam, and generates a new hologram according to the modulated energy and position information, and the beam parameter control component generates a new laser beam according to the new hologram. The laser beam is incident on the spot energy and position sensing component 12, and returns to the above step 12;

Step 14 : generating multiple laser beams according to the holograms corresponding to the energy and position information of all laser beams whose real-time state matches the preset state, and the multiple laser beams are incident on the target area.

The control method of the three-dimensional multi-beam laser parameter control system of the present invention is to sequentially and accurately collect the energy and position information, and perform closed-loop feedback control, dynamically adjust the energy and position information of each laser beam, monitor the parameter information and quality of the output beam in real time, and have flexible control. Each laser beam to the target area reaches the corresponding set target, effectively reducing the optical system error, and the energy and position information of each laser beam can be arbitrarily controlled in the three-dimensional space to meet the requirements of each laser beam in the target area. Both can achieve arbitrary and precise modulation, and double the laser utilization rate to meet the requirements of practical application scenarios.

In the present invention, in order to make the output multi-beams have high-quality and arbitrary illumination effects for different local areas when the output multi-beams are incident on the target area, it is necessary to pre-set the spatial positions of the target multi-beams and the parameters used to characterize the multi-beam parameter information. The threshold value is convenient for comparison to determine whether the set requirements are met when the energy and position information are subsequently collected on the spot energy and position sensing component 12 .

In one or more embodiments of the present invention, in step 11, initializing the laser system specifically includes:

Step 111 : superimpose the random initial phase on the incident light field, and perform Fourier transform to obtain the corresponding light field distribution of the surface where the frequency domain is located, the amplitude of the surface light field where the frequency domain is located, and the phase of the surface where the frequency domain is located;

Step 112: Substitute the preset target light field amplitude for the amplitude of the surface light field where the frequency domain is located, and perform inverse Fourier transform according to the phase of the surface where the frequency domain is located, to obtain the updated light field distribution and spatial domain where the air domain is located. The amplitude of the light field on the surface and the phase of the surface where the space is located;

Step 113: generate a hologram according to the updated light field distribution of the surface where the airspace is located, the light field amplitude of the surface where the airspace is located, and the phase of the surface where the airspace is located;

Step 114: Load the hologram onto the laser system, and the laser system generates multiple laser beams according to the hologram.

Fourier transform is performed on the random initial phase to generate the light field distribution of the surface where the frequency domain is located, the light field amplitude of the surface where the frequency domain is located, and the phase of the surface where the frequency domain is located as a reference, and the target light field amplitude is used to replace the light field amplitude of the surface where the frequency domain is located. , to obtain the phase-generated hologram of the plane where the air domain is located, so as to determine the corresponding hologram, and it is convenient for the beam parameter control component to generate multiple laser beams according to the hologram.

Here, after the hologram is loaded on the laser system, the laser system generates multiple laser beams according to the hologram.

In one or more embodiments of the present invention, in step 12, the sequentially collecting the energy and position information of all laser beams whose focal points are not in the same plane specifically includes the following steps:

Step 121: the spot energy and position sensing assembly 12 receives multiple laser beams, and generates a corresponding contour according to the laser beam whose focus is located on the plane where the spot energy and position sensing assembly 12 is located;

Step 122: Collect the actual energy value I _i and the actual position coordinate P _i corresponding to all the light spots within the contour range;

Step 123: Adjust the relative positions of the spot energy and position sensing assembly 12 and the focal points of the multiple laser beams, and repeat the above steps 121 and 122 until the actual energy values I _i and actual position coordinates P corresponding to all laser beams _i Collection is complete.

By adjusting the relative position of the spot energy and position sensing component 12 and the focal point of the corresponding laser beam, the collection of energy and position information of the laser beam with the focal point on different planes is realized, so that the final output can be achieved through subsequent closed-loop feedback control. The energy and position information of each laser beam can achieve the purpose of setting the target, and realize the targeted control of each laser beam in the three-dimensional space.

In one or more embodiments of the present invention, in step 123, the specific implementation of adjusting the relative position of the spot energy and position sensing component 12 and the focal points of the multiple laser beams is as follows:

By adjusting the distance between the focal point of the laser beam emitted by the laser system and the spot energy and position sensing component 12, it can be ensured that the focal point of each laser beam can be located at the spot energy and position transmission during the adjustment process. The plane where the sensing component 12 is located can be accurately collected.

In practice, the spot energy and position sensing assembly 12 can be arranged on the linear displacement stage, and can move up and down together with the linear displacement stage (z-direction) to adjust the focus of the laser beam emitted by the laser system. The distance between the spot energy and the position sensing component 12, and the parameter information of the laser beam is collected when the focal point of the laser beam is located on the plane where the spot energy and position sensing component 12 is located.

In one or more embodiments of the present invention, in step 123, the specific implementation of adjusting the relative position of the spot energy and position sensing component 12 and the focal points of the multiple laser beams is as follows:

A Fresnel lens phase hologram with adjustable parameters and a focal length shift function is superimposed on the hologram, and the focus of the stress beam is adjusted to the spot energy and position by adjusting the parameters of the Fresnel lens The sensing assembly 12 is located on a plane, so that the spot energy and position sensing assembly 12 collects energy and position information of the corresponding laser beam.

A Fresnel lens phase hologram with adjustable focal length shift function superimposed on the hologram is used, and by adjusting the parameters of the Fresnel lens, the focus of the stress beam is adjusted to the spot energy and position On the plane where the sensing component 12 is located, it is possible to detect the light spots of different focal planes without moving the spot energy and position sensing component 12, so as to realize fast three-dimensional position detection and feedback without mechanical movement. This method does not require mechanical movement, so it has the advantages of high speed and accurate positioning.

As shown in FIG. 2 , for each laser beam, by adjusting the relative positions of the spot energy and position sensing component 12 and the focal points of multiple laser beams, the focal points of the corresponding laser beams are exactly located at the spot energy and position The plane where the sensing component 12 is located, and then the energy and position information are collected. It can be seen that after feedback modulation, the energy and location of the laser beam collected by the spot energy and the position sensing component 12 are different, all reaching The corresponding set target can meet the arbitrary and precise regulation of multiple laser beams. In this way, each laser beam is separately feedback modulated, so that the energy and position information of multiple laser beams in three-dimensional space can match the corresponding preset. Set target parameter information.

In particular, in practical applications, in a specific application scenario, it is necessary to use multiple uniform laser beams to irradiate the target area. The laser parameters (energy, brightness, etc.) of the beam are kept the same, and the target area is irradiated to achieve the effect of uniform irradiation, as shown in Figure 3.

In practice, it is necessary to generate a plurality of circular contours with the same shape as the target beam according to each laser beam and perform scaling adjustment to ensure that the multiple circular contours can frame all the laser beams collected by the spot energy and position sensing component 12. By adjusting the circular outline to a suitable size, it is ensured that the circular outline can be framed by a suitable laser beam to collect the corresponding energy and position information.

In one or more embodiments of the present invention, in step 12, the step of judging whether the real-time energy and position information of each laser beam matches the corresponding preset energy and position information further includes:

Determine whether the actual energy value I _i and the actual position coordinate P _i meet the preset matching conditions, and when the preset matching conditions are met, determine that the energy and position information of the laser beam match the corresponding preset target energy and position information , otherwise it does not match;

The preset matching conditions are:

𝛥 I _i = I _i - I _i—targ

𝛥 P _i = P _i - P _i—targ

𝛥 I _i <I𝜀

𝛥 P _i < P𝜀

Among them, I _i is the actual energy value of the i -th laser beam, I _i-targ is the target energy value of the i -th laser beam, P _i is the actual position coordinate of the i- th laser beam, and P _i-targ is the i -th laser beam The target position coordinates of the laser beam, 𝛥 I _i is the energy deviation value between the actual energy value of the ith laser beam and the target energy value, 𝛥 P _i is the actual position coordinates of the ith laser beam and the target position coordinates. Position coordinate deviation value, I𝜀 is the preset energy deviation threshold, P𝜀 is the preset position coordinate deviation threshold.

Through the above formula, it can be judged whether each laser beam meets the corresponding preset requirements, and iterative processing is performed when the preset requirements are not met, so as to finally realize that each laser beam output to the target area meets the preset target. , to achieve targeted control of multiple laser beams irradiated to the target area in three-dimensional space to meet the arbitrary and precise control requirements of multiple laser beams.

In one or more embodiments of the present invention, in step 13, the specific method for modulating the energy and position information of the mismatched laser beams is:

Step 131: Correct according to the energy deviation value and the position coordinate deviation value, and the specific calculation formula is:

G _Ii =M _i *𝛥 I _i + I _i—targ

G _Pi =N _i *𝛥 P _i + P _i—targ

Step 132: Determine the updated image plane transformation phase and image plane light field amplitude according to the corrected energy value and position coordinate value;

Step 133: Perform inverse Fourier transform according to the updated image plane light field amplitude and the image plane transformation phase to obtain the modulated image plane light field amplitude and the modulated phase;

Wherein, M _i is the energy weighting coefficient of the i - th laser beam, N _i is the position coordinate weighting coefficient of the i-th laser beam, I _i-targ is the target energy value of the i- th laser beam, P _i-targ is the target position coordinate of the i -th laser beam, G _Ii is the corrected energy value of the i -th laser beam, G _Pi is the corrected position coordinate value of the i -th laser beam, and the value range of i is [1, k ], k is the total number of laser beams.

By using the above method to modulate the energy and position information, it can be corrected when the energy and position information of the laser beam do not match the corresponding preset target energy and position information, and the cycle is repeated until the energy and position of each laser beam are The position information is matched with the corresponding preset target energy and position information, so as to ensure that each laser beam incident on the workpiece surface reaches the corresponding set target, so as to meet the arbitrary and precise control requirements of multiple laser beams.

It should be pointed out that the selection of the weight coefficient will cause the matching convergence speed to be different during the loop iteration (the speed at which the calculation reaches the matching), and the selection of the weight coefficient will also lead to the final calculation of the arbitrary control effect. In the embodiment of the present invention, the ranges of the energy weight coefficient and the position coordinate weight coefficient are both selected to be between 0 and 1.

Compared with the prior art, the three-dimensional multi-beam laser parameter control method of the present invention has the control function of parallel multi-beam multi-parameter parameters, so as to realize the control of the number, shape and focus position of the laser beam, and the energy distribution of the strong laser beam, During the modulation process, by loading different holograms, the position, quantity and energy of the multi-beam can be flexibly adjusted, which can flexibly meet the requirements of various laser control application scenarios; at the same time, a feedback mechanism is added, and the spot energy and position sensing components are used. 12, as a light intensity collector, monitors the state and quality of the output beam in real time, and feeds back its parameterization to the control terminal 16 for adjustment, which solves the problem that the existing technology is difficult to accurately control the energy and position of multiple light spots.

The three-dimensional multi-beam laser parameter control method of the present invention can be widely used in medicine, optics, physics, microelectronics and laser communication, laser processing, laser radar, laser 3D printing and device forming (such as glass edge forming and optical fiber surface and Internal molding) and other technical fields, the application prospect is very broad.

Example 2

As shown in FIG. 4, a three-dimensional multi-beam laser parameter control system includes a laser light source 1 for generating coherent laser beams, a beam parameter control component 4, a flip mirror 9, a first focusing component 10, spot energy and position sensing The assembly 12, the second focusing assembly 14, the three-dimensional motion table 15 and the control terminal 16, the laser light source 1, the beam parameter control assembly 4 and the flip mirror 9 are connected in order by optical paths, and the flip mirror 9 can be freely rotated so that the The laser beam is incident on the spot energy and position sensing component 12 via the first focusing component 10, or is incident on the workpiece on the three-dimensional motion table 15 via the second focusing component 14, and the first The distance between the focal point of the laser beam emitted by a focusing assembly 10 and the spot energy and position sensing assembly 12 is relatively adjustable, and the control terminal 16 is respectively connected to the beam parameter control assembly 4, spot energy and position sensing assembly The assembly 12 , the linear displacement stage 11 and the three-dimensional motion table 15 are electrically connected.

The control terminal 16 is used to initialize and generate a hologram of the output light field, and load the hologram onto the beam parameter control component 4; the beam parameter control component 4 receives the output of the laser light source. Laser beams, multiple laser beams are generated according to the hologram, and the multiple laser beams pass through the optical path to the flip mirror 9 for reflection and then enter the spot energy and position sensing assembly 12 through the first focusing assembly 10, or Incident on the workpiece via the second focusing assembly 14; the spot energy and position sensing assembly 12 receives the laser beam, and sequentially collects laser parameter information of all laser beams whose focal points are not in the same plane; the control terminal 16 is also used to judge whether the laser parameter information of each laser beam matches the corresponding preset target laser parameter information, and control the beam parameter control assembly 4 to correspond according to the laser parameter information of all laser beams when matching. The hologram generates multiple laser beams; and in the case of mismatch, iterative modulation processing is performed according to the laser parameter information of each laser beam, until the laser parameter information of each laser beam and the corresponding preset target laser parameter information match.

The three-dimensional multi-beam laser parameter control system of the present invention accurately collects the parameter information of each laser beam in turn by adjusting the distance between the focus of the outgoing laser beam and the spot energy and position sensing component 12, and feeds it back to the control system. The terminal 16 performs closed-loop feedback control, dynamically adjusts the parameter information of each laser beam, monitors the parameter information and quality of the output beam in real time, and has flexible control. Each laser beam achieves the corresponding set target, effectively reducing the optical system error, and each laser beam can be controlled in a three-dimensional space to meet the needs of each laser beam in the target area. ground modulation, and doubled the laser utilization rate to meet the requirements of practical application scenarios.

In one or more embodiments of the present invention, the three-dimensional multi-beam laser parameter adjustment system further includes a polarization direction and energy adjustment component 2, a first mirror 3, a first lens 5, a second mirror 6, a Three reflecting mirrors 7 and a second lens 8, the polarization direction and energy adjustment assembly 2 and the first reflecting mirror 3 are arranged between the laser light source 1 of the laser beam and the beam parameter adjustment assembly 4, and the laser light source 1 , the polarization direction and energy adjustment assembly 2, the first reflecting mirror 3 and the beam parameter adjustment assembly 4 are sequentially connected by optical paths, and the first lens 5, the second reflecting mirror 6, the third reflecting mirror 7 and the second lens 8 are arranged in Between the beam parameter control assembly 4 and the flip mirror 9, and between the beam parameter control assembly 4, the first lens 5, the second reflector 6, the third reflector 7, the second lens 8 and the flip mirror 9 Sequential optical path connection. By setting the polarization direction and energy adjustment component 2, the laser beam emitted from the laser light source 1 can be adjusted, so that the laser beam is reflected by the first reflector 3 and then incident on the beam parameter adjustment component, and passes through the The first lens 5 is focused, the second reflecting mirror 6 is reflected, the third reflecting mirror 7 is reflected, and the second lens 8 is focused and then incident on the flip mirror 9, so as to facilitate subsequent feedback adjustment.

Here, the polarization direction and energy adjustment assembly 2 adopts a glass slide and a polarization beam splitter, and its function is to ensure that the polarization direction and energy of the output beam adapt to the beam parameter adjustment assembly 4, and the function of the beam parameter adjustment assembly 4 is to change the space On the amplitude or intensity, phase, polarization state and diffraction angle of the light distribution, the function of the spot energy and position sensing component 12 is to collect the laser parameter information of the laser beam with the focal point on the plane where it is located in real time, so as to determine the quality of the laser beam. for real-time monitoring.

In order to achieve accurate control of each beam parameter, it is necessary to locate the spatial position (x, y, z) of the three-dimensional focus after focusing, and the light spot energy and position sensing component 12 can only detect the two-dimensional plane (x, y). ) for positioning, the other dimension (z-direction) requires movement of the physical position to achieve.

Optionally, in one or more embodiments of the present invention, the three-dimensional multi-beam laser parameter control system further includes a linear displacement stage 11, and the spot energy and position sensing assembly 12 is located on the linear displacement stage 11. up and down together with the linear displacement stage 11 (z-direction) to adjust the distance between the focus of the laser beam emitted by the first focusing assembly 10 and the spot energy and position sensing assembly 12 , and the parameter information of the laser beam is collected when the focal point of the laser beam is located on the plane where the light spot energy and position sensing component 12 is located. The linear displacement stage 11 can drive the spot energy and position sensing assembly 12 to move up and down, so as to adjust the distance between the focus of the laser beam emitted from the first focusing assembly 10 and the spot energy and position sensing assembly 12 In this way, it can be ensured that the focus of each laser beam can be located on the plane where the spot energy and position sensing component 12 is located during the adjustment process, so that it can be accurately collected.

Optionally, in one or more embodiments of the present invention, the beam parameter adjustment component 4 is further configured to superimpose a Fresnel lens with adjustable parameters on the hologram, and adjust the Fresnel lens by adjusting the parameters. The parameters of the lens adjust the distance between the focal point of the laser beam and the spot energy and position sensing component 12, and collect the parameter information of the laser beam when the focal point of the laser beam is located on the plane where the spot energy and position sensing component 12 is located . By superimposing a Fresnel lens with adjustable parameters on the hologram, a phase hologram with a focal length shift function can be superimposed on the hologram, and it is possible to detect different energy and position sensor components 12 without moving the spot energy. The light spot on the focal plane realizes fast three-dimensional position detection and feedback without mechanical movement.

In one or more embodiments of the present invention, the light beam parameter control component 4 adopts a programmable diffractive optical device. Using programmable diffractive optical devices to divide a single laser beam into multiple parallel laser beams, it can scan multiple paths at the same time, which doubles the energy utilization rate of the laser, and can obtain a large refractive index change at a low voltage, which is easy to use. It can be made into a three-dimensional shape, so it is easy to form a device for parallel optical information processing, and it has the function of regulating multiple parameters of parallel multi-beam to realize the control of the number, shape and focus position of the laser beam, as well as the energy distribution of the strong laser beam. It has the advantages of simple production, low price, low energy consumption and easy control.

In particular, in practice, in order to adjust the distance between the focal point of the laser beam emitted by the first focusing assembly 10 and the spot energy and position sensing assembly 12, a software adjustment method can also be used, specifically: using The programmable diffractive optical device can superimpose a Fresnel lens phase hologram with adjustable parameters and focal length shift function on the basis of the hologram corresponding to the original multi-beam, and by adjusting the parameters of the Fresnel lens, the corresponding The focal point of the laser beam is adjusted to the plane where the spot energy and position sensing assembly 12 is located, so that the spot energy and position sensing assembly 12 collects parameter information corresponding to the laser beam to realize that all three-dimensional focusing points can be located in the Spot energy and position sensing assembly 12 and detected. This method does not require mechanical movement, so it has the advantages of high speed and accurate positioning.

Optionally, in one or more embodiments of the present invention, the flip mirror 9 is an electric flip mirror, and the control terminal 16 is electrically connected to the electric flip mirror, and controls the electric flip mirror to rotate, So that the multiple laser beams perform optical path switching between being incident on the light spot energy and position sensing assembly 12 and incident on the workpiece. By controlling the flip of the electric flip mirror, the optical path can be automatically switched after the feedback adjustment of the laser beam emitted by the laser light source 1 is completed, so as to ensure that the laser beam after the modulation is automatically switched to the workpiece, and the automatic control improves the intelligence of the entire system. degree.

In the present invention, the second focusing assembly 14 may use a galvanometer, a focusing mirror or a high-power objective lens, etc., and cooperate with a corresponding optical path to achieve a focusing effect.

In the three-dimensional multi-beam laser parameter control system of the present invention, after the laser light generated by the laser light source 1 is adjusted by the polarization direction and the energy adjustment component 2, it is reflected on the beam parameter control component 4 through the first reflecting mirror 3, and the beam parameter The regulating component 4 is modulated and focused by the first lens 5 , and then reflected by the second mirror 6 , the third mirror 7 and the second lens 8 , and then incident on the flip mirror 9 . After reflection, it is focused by the first focusing assembly 10 and then incident on the spot energy and position sensing assembly 12. The spot energy and position sensing assembly 12 detects the laser parameters of the laser beam and performs feedback control until all laser beams are After the laser parameters are matched with the corresponding target laser parameters, the flip mirror 9 is controlled to flip, so that the laser beam is reflected by the flip mirror 9 and then incident on the fourth reflector 13 , and then passes through the fourth reflector 13 after being reflected by the fourth reflector 13 . The second focusing component 14 focuses and finally enters the target area.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (6)

1. A three-dimensional multi-beam laser parameter regulation method is characterized by comprising the following steps:

step 11, initializing a system to obtain a hologram of an output light field, and generating a plurality of laser beams according to the hologram, wherein the laser beams are incident to a detection area;

step 12: adjusting the distance between the outgoing laser beam and the detection assembly in the detection area, sequentially detecting the energy and position information of all laser beams incident to different planes, judging whether the real-time energy and position information of each laser beam are matched with the corresponding preset energy and position information of the laser beam, if so, matching the real-time state of the laser beam with the preset state, and entering step 14, otherwise, entering step 13;

step 13: modulating the energy and position information of the unmatched laser beams, generating a new hologram according to the modulated energy and position information, generating a new laser beam according to the new hologram, enabling the new laser beam to be incident to the detection area, and returning to the step 12;

step 14: generating a plurality of laser beams according to the holograms corresponding to the energy and position information of all the laser beams with the real-time state matched with the preset state, wherein the laser beams are incident to a target area;

in step 12, the step of determining whether the real-time energy and position information of each laser beam match the corresponding preset energy and position information further includes:

actual energy value I of any laser beam_iAnd actual position coordinates P_iIf the following preset matching conditions are met, matching the real-time energy and the position information of the laser beam with the corresponding preset energy and position information, otherwise, mismatching;

the preset matching conditions are as follows:

ΔI_i＝I_i-I_i—targ

ΔP_i＝P_i-P_i—targ

ΔI_i<Iε

ΔP_i<Pε

wherein, I_iIs the actual energy value of the ith laser beam, I_i—targIs a target energy value, P, of the ith laser beam_iIs the actual position coordinate, P, of the ith laser beam_i—targIs a target position coordinate, Δ I, of the ith laser beam_iIs the energy deviation value, delta P, between the actual energy value and the target energy value of the ith laser beam_iThe deviation value of the position coordinate of the actual position coordinate of the ith laser beam and the target position coordinate is shown, I epsilon is a preset energy deviation threshold value, and P epsilon is a preset position coordinate deviation threshold value;

in step 13, the step of modulating the energy and the position information of the unmatched laser beam further includes:

step 131: correcting according to the energy deviation value and the position coordinate deviation value, wherein the specific calculation formula is as follows:

G_Ii＝M_i*ΔI_i+I_i—targ

G_Pi＝N_i*ΔP_i+P_i—targ

step 132: determining the updated image plane transformation phase and the image plane light field amplitude according to the corrected energy value and the position coordinate value;

step 133: performing inverse Fourier transform according to the updated image plane light field amplitude and the updated image plane transformation phase to obtain a modulated image plane light field amplitude and a modulated phase;

wherein, M is_iIs the energy weight coefficient, N, of the ith laser beam_iIs a position coordinate weight coefficient of the ith laser beam, I_i—targIs a target energy value, P, of the ith laser beam_i—targIs the target position coordinate of the ith laser beam, G_IiFor the corrected energy value of the i-th laser beam, G_PiThe corrected position coordinate value of the ith laser beam is set as the value range of [1, k ]]And k is the total number of laser beams.

2. The three-dimensional multi-beam laser parameter adjustment and control method according to claim 1, wherein in the step 11, the step of initializing the system further comprises:

step 111: superposing the random initial phase to an incident light field, and performing Fourier transform to obtain corresponding optical field distribution of the surface where the frequency domain is located, the amplitude of the optical field of the surface where the frequency domain is located and the phase of the surface where the frequency domain is located;

step 112: replacing the preset target light field amplitude with the light field amplitude of the surface where the frequency domain is located, and performing inverse Fourier transform according to the phase of the surface where the frequency domain is located to obtain updated surface light field distribution of the space domain, the light field amplitude of the surface where the space domain is located and the phase of the surface where the space domain is located;

step 113: generating a hologram according to the updated optical field distribution of the plane of the airspace, the amplitude of the optical field of the plane of the airspace and the phase of the plane of the airspace;

step 114: loading the hologram onto a laser system that generates a plurality of laser beams from the hologram.

3. The method for controlling the parameters of the three-dimensional multi-beam laser as claimed in claim 2, wherein in the step 12, the detection area is provided with a light spot energy and position sensing component, and the energy and position information of all the laser beams with the focuses not on the same plane are sequentially collected by the light spot energy and position sensing component, further comprising:

step 121: the light spot energy and position sensing assembly receives a plurality of laser beams and generates a corresponding outline according to the laser beams with the focal points positioned on the plane where the light spot energy and position sensing assembly is positioned;

step 122: collecting actual energy values I corresponding to all light spots in the profile range_iAnd actual position coordinates P_i；

Step 123: adjusting the relative position of the spot energy and position sensing assembly and the focal point of the plurality of laser beams, and repeating the above steps 121 and 122 until the actual energy values I corresponding to all the laser beams are reached_iAnd actual position coordinates P_iAnd finishing the collection.

4. The method for three-dimensional multi-beam laser parameter manipulation of claim 3 wherein the step of adjusting 123 the relative position of the spot energy and position sensing assembly to the focal points of the plurality of laser beams further comprises:

and adjusting the distance between the focal point of the laser beam and the spot energy and position sensing assembly so that the spot energy and position sensing assembly acquires the energy and position information of the laser beam when the focal point of the laser beam is positioned on the plane where the spot energy and position sensing assembly is positioned.

5. The method for three-dimensional multi-beam laser parameter manipulation of claim 3 wherein the step of adjusting 123 the relative position of the spot energy and position sensing assembly to the focal points of the plurality of laser beams further comprises:

and superposing a Fresnel lens phase hologram with adjustable parameters and a focal length offset function on the hologram, and adjusting the focus of the corresponding laser beam to the plane where the light spot energy and position sensing assembly is located by adjusting the parameters of the Fresnel lens so that the light spot energy and position sensing assembly acquires the energy and position information of the corresponding laser beam.

6. A three-dimensional multi-beam laser parameter regulation and control system is used for realizing the method of claim 1 and is characterized by comprising a laser light source, a light path deflection component, a beam parameter regulation and control component, a light spot energy and position sensing component and a control terminal, wherein the beam parameter regulation and control component, the light spot energy and position sensing component and the control terminal are respectively connected with the control terminal;

the control terminal is used for initializing and generating a hologram of an output light field, and loading the hologram onto the light beam parameter regulation and control component;

the optical path deflection assembly is used for enabling a plurality of laser beams to be incident on the light spot energy and position sensing assembly positioned in the detection area or the working plane positioned in the target area;

the beam parameter regulating and controlling component is used for receiving the laser beams output by the laser light source and generating a plurality of laser beams according to the hologram;

the light spot energy and position sensing assembly is used for receiving the laser beams and sequentially collecting energy and position information of all the laser beams with focuses not on the same plane;

the control terminal is further used for judging whether the energy and position information of each laser beam is matched with corresponding preset energy and position information or not, and controlling the light beam parameter regulation and control assembly to generate a plurality of laser beams according to holograms corresponding to the energy and position information of all the laser beams during matching; and when the laser beams are not matched, carrying out iterative modulation processing according to the energy and the position information of each laser beam until the energy and the position information of each laser beam are matched with the corresponding preset energy and position information.

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